US20040015049A1 - Endoscope with sideview optics - Google Patents

Abstract

An endoscope (1) is proposed with a rotatable side-viewing optics system (11), which has a mirror (15) for deflecting light onto an object to be examined and for reflecting the image of the object. A video camera (7) is located inside a hollow cylinder (6) that can be moved in rotation and the side-viewing optics system (11) is mechanically connected to the hollow cylinder (6) on the side that faces away from the viewing direction (12) of the video camera (7).

Description

STATE OF THE ART
• The invention starts from an endoscope with sideview optics according to the category of the main claim.[0001]
• Endoscopes with sideview systems for viewing and critically examining tubular inside walls and joints are known from the state of the art, with which a desired deviation of the field of view can be achieved. For this purpose optical systems can be used which consist of a deviation optics that can be rigidly mounted to an endoscope or a tubular camera, but which do not have a motor driven swivel head, so that only a small area of the tube inside wall can be examined. To enlarge the field of view of the tubular camera, an optics was created with a continuous 360° panoramic view, which allows a view of the tube inside wall along with the view of the front. Such an enlargement of the field of view is however, accompanied by a very burdensome reduction of the illumination of the wall areas to be examined.[0002]
• To focus the existing light quantity on smaller areas for the purpose of improving the illumination and still be able to optically examine larger inside wall areas, endoscopes were proposed in which the camera is arranged on a motor driven swiveling and/or tilting device. Such a swiveling device for an endoscope is known from DE-OS 43 29 162, which consists of a disc-shaped end piece connected with three piezoelectric drive elements at three points, on which a camera chip is attached. Depending on the drive of the driving elements, the end piece can be deviated at an angle which is very much smaller than 90°.[0003]
• This problem of being able to deviate the direction of view by 90° opposite the longitudinal axis of the endoscope is solved by a known endoscope with a tube camera by arranging in the direction of the object to be photographed in front of the camera a motor driven and rotatable mirror around the longitudinal axis of the endoscope which can be swiveled opposite the longitudinal axis in such a way that it can occupy any desired angle opposite it. The motor forms a constructive unit with the mirror, which is connected with the tube camera by means of several crosspieces. In particular with smaller endoscopes these crosspieces may not exceed a certain strength, so that as a result the reflected image of the object to be examined can be disturbed, by for example having deciding damaged areas of the tube inside wall covered by a crosspiece. Moreover, these crosspieces can get into the cone of the light illuminating the inside wall, so that shadows are formed, which can also result in the damaged areas of the object to be examined remaining undetected. Further, there is the danger that crosspieces will reflect the light serving for illumination, so that a video camera with automatic exposure setting picks up the strongly illuminated crosspiece, but not the darker background, i.e. the object to be examined.[0004]
THE INVENTION AND ITS ADVANTAGES
• The endoscope of the invention with sideview optics has the advantage over the previously mentioned endoscopes of making possible an endoscopic view of objects that are difficult to access, in which the light serving to illuminate the object reaches the object unhindered and the image of the object to be examined is reflected by a sideview optics to the lens of a video camera used for this purpose undisturbed.[0005]
• In accordance with an advantageous embodiment of the invention, the video camera is surrounded by a cylinder-shaped casing, which forms a clearance with the hollow cylinder and that on the casing at least one gasket is arranged for sealing of the clearance. This prevents dampness or dirt from penetrating into the interior of the endoscope, which can impair its operability.[0006]
• In accordance with a further advantageous embodiment of the invention, the electric motor has a gear with which the hollow cylinder can be rotated by means of a hollow gear arranged on its cylinder inner wall. As a result, it is possible to arrange either only the camera or in addition also the electric motor within the hollow cylinder.[0007]
• In accordance with a further advantageous embodiment of the invention, a transmission is arranged between the electric motor and the gear, with which the speed of the electric motor can be reduced in suitable fashion.[0008]
• In accordance with a further advantageous embodiment of the invention, the video camera is mechanically connected with the electric motor. This makes it possible to support the rotating hollow cylinder, depending on the embodiment of the invention, either only on the casing of the video camera or on the joint casing of the electric motor and the video camera, which gives the endoscope of the invention a great mechanical strength.[0009]
• In accordance with a further advantageous embodiment of the invention, the sideview optics is connected with the hollow cylinder by means of a semi-tubular attachment, which permits an unhindered illumination and view of the object to be examined and results in a stable mounting support of the sideview optics on the hollow cylinder.[0010]
• In accordance with a further advantageous embodiment of the invention, the mirror of the sideview optics is constructed as a prism, which has an improved reflectivity compared with conventional mirrors.[0011]
• In accordance with a further advantageous embodiment of the invention, the electric motor can propel the hollow cylinder by means of a friction gear, which in particular with small endoscopes can be implemented at a very favorable price.[0012]
• In accordance with a further advantageous embodiment of the invention, the electric motor is constructed as a stepping motor, which consists of electrical windings arranged on the casing and of permanent magnets arranged on the hollow cylinder that enter into electromagnetic interaction with the windings depending on their drive. Such motors are especially easy to construct and thus can also be manufactured cost-effectively. In particular, however, these motors allow a very exact positioning of the sideview optics of the invention.[0013]
• In accordance with a further advantageous embodiment of the invention, a device for the coupling of light to the fiber optic light guide with a mounting support of the end of the fiber optic light guide turned toward the photo camera that swivels in such a way that in a first swivel position of the mounting support a maximum and in a second swivel position of the mounting support a minimum light quantity can be coupled in the frontal area of the end of the fiber optic light guide attached to the mounting support. As a result, the quantity of the light coupled in the fiber optic light guide and serving for the illumination of the object to be examined can be precisely adapted to the structure of this object.[0014]
• In accordance with a further advantageous embodiment of the invention, the device has a lamp with a light-focusing reflector, that the fiber optic light guide is attached to the mounting support with the frontal area pointing in the direction of the reflector, and that the mounting support can be swiveled around a vertical axis lying between the light focus and the reflector between the first and the second swivel positions. As a result of this, it is easy, depending on the swivel position, to have the frontal area of the fiber optic light guide reach the light focus of the reflector in such a way that a precisely measurable light quantity is coupled in the fiber optic light guide.[0015]
• In accordance with a further advantageous embodiment of the invention, a motor driven rotating arm is provided for swiveling the mounting support, which is mechanically connected with the mounting support by means of a rod and a bolt arranged outside of the axis. Although the of the invention is very simply constructed, it allows a very exact positioning of the frontal area of the fiber optic light guide opposite the cone of light radiated by the reflector.[0016]
• In accordance with a further advantageous embodiment of the invention, the electric motor is connected with the hollow cylinder by means of a flexible shaft and a miniature gear. This allows the arrangement of the electric motor rotating the hollow cylinder and with it the sideview optics at the distance of the endoscope to any place of the probe, making it possible to further reduce the exterior dimensions of the endoscope. The separation of the mechanically fixed connection between the electric motor and video camera caused by the construction of the invention also makes it possible to move the endoscope through tube turns with a very small radius, to examine their inside area.[0017]
• In accordance with a further advantageous embodiment of the invention, the camera has an adjustable lens, which, in order to be adjusted, is connected by means of a flexible shaft to an electric motor. This makes it possible to control the adjustment of the lens from the outside, which ensures that the images of the objects to be investigated are always sharp and well recognizable.[0018]
• Further advantages and advantageous embodiments of the invention can be gathered from the following example description, the drawings and the claims.[0019]
DRAWING
• An embodiment of the invention is shown in the drawings and described in greater detail. The drawing show the following:[0020]
• FIG. 1 an endoscope with a sideview in section.[0021]
• FIG. 2 a section through a device for coupling of light to a fiber optic light guide along the broken line II-II in FIG. 3,[0022]
• FIG. 3 top view of the device for coupling of light to the fiber optic light guide and[0023]
• FIG. 4 an embodiment of the endoscope in which the lens of the video camera and the sideview optics are driven by means of flexible shafts.[0024]
DESCRIPTION OF THE EMBODIMENT
• In FIG. 1 an[0025]endoscope1 is shown with aprobe2 and aphoto camera3 attached to it. Thephoto camera3 has acasing4 connected with theprobe2 for anelectric motor5 and a rotatinghollow cylinder6 connected to it, in whose interior avideo camera7 in miniature format is arranged, as normally used for endoscopes and which is not explained in detail here. Thevideo camera7 is connected to a device for evaluating the supplied video signals by means of an electrical line conducted in theprobe2 and not shown in the figure and is connected with thecasing8 of theelectric motor5, which by means of a gear9 thus can only rotate thehollow cylinder6, which for this purpose in the area of the gear9 has a hollow gear not shown in detail. Further, for this purpose there is atransmission10 between theelectric motor5 and the gear9 which reduces the speed of theelectric motor5 in suitable fashion. During one rotation of thehollow cylinder6 thevideo camera7 remains motionless at rest relative to theelectric motor5. In the process the rotary movement of theelectric motor5 and with it of thehollow cylinder6 can be controlled as desired by means of the conductors guided in theprobe2 which are not shown in the figure. In the present embodiment thevideo camera7 is surrounded by a cylinder-shaped casing19, which forms a clearance with the hollow cylinder. To prevent dampness or dirt from penetrating into this clearance, which could impair the operability of the electric drive (5,9,10),gaskets20 are arranged between the casing19 and thehollow cylinder6.
• On the side turned toward the direction of view indicated by the arrow[0026]12 asideview optics11 is attached to thehollow cylinder6, which thus turns along with thehollow cylinder6. Thesideview optics11 consists essentially of a semi-tubular attachment whose one side is connected with thehollow cylinder6 and on whose other end amount14 for amirror15 is located, which in the present embodiment is constructed as a prism. With thelongitudinal axis18 of theendoscope1 themirror15 encloses an angle of 45° in the present embodiment. Depending on the purpose of theendoscope1, however, this angle can also have a different value. If light is added by means of a fiberoptic light guide16 of thevideo camera7 conducted laterally on theelectric motor5 and radiated over the frontal area of the fiberoptic light guide16 in a manner not shown in detail, as a result of this the light is deviated and projected in the direction of thearrow12 on the object to be examined in greater detail. The image of the object illuminated thereby is reflected by themirror15 to thelens17 of thevideo camera7 and can thus be picked up by it. In particular when in this fashion the inside wall of a tube is optically scanned, the entire inside wall of the tube to be appraised can be examined by means of a rotation of thesideview optics11 caused by the electric motor via thehollow cylinder6.
• The[0027]electric motor5 can not only be arranged behind thevideo camera7, as shown in the figure, but rather also can be arranged next to it. In this case, which is not shown in the drawing, thevideo camera7 is arranged in the same casing as theelectric motor5, andvideo camera7 andelectric motor5 are arranged within thehollow cylinder6 driven by gear or friction wheel byelectric motor5, with the sideview optics being attached to said hollow cylinder.
• It is also conceivable to replace the[0028]electric motor5 by means of a stepping motor, in which electrical windings are arranged on the casing19 of thevideo camera7 and thehollow cylinder6 is equipped with permanent magnets. Depending on the desired direction of view the corresponding electrical windings are triggered, which then exercise attractive or repulsive forces on the permanent magnets and thus turn thesideview optics11 in the desired position.
• The[0029]endoscope1 with thesideview optics11 of the invention has hereby in particular the advantage that through its attachment to the side turned toward the direction of view by means of thesemi-tubular attachment13 no disturbing attachment crosspieces disturb the path of the rays and the image of the object to be examined.
• In FIGS. 2 and 3 a device is shown with whose help the light can be coupled in the fiber optic[0030]light guide16, which illuminates the object to be examined with theendoscope1. In FIG. 3 thedevice21 is shown in top view, and FIG. 2 shows a section through thedevice21 along the broken line II-II drawing in FIG. 3. Thedevice21 consists of a lamp attached in arack22, of which for simplicity's sake only thereflector23 is drawn in FIGS. 2 and 3. Said reflector is attached to alamp bracket24, which is constructed as an electric plug, whose connectingpins25 and25′ each plug into ajack26,26′ with connection to theelectric power supply27.
• On the side turned toward the power supply[0031]27 aplate28 is attached to therack22, to which a mountingsupport29 for the end of the fiber opticlight guide16 is pivoted around avertical axis30. Aprojection31 of therack22 forms with the right end of the plate28 a recess, in which aprojection32 of the mountingsupport29 and by means of a bolt not shown in the figures inserted in thebore33 of therack22 and thebore34 of theprojection32 is held in such a way with a longitudinal axis lying parallel toaxis30 that rotating motions of the mountingsupport29 around theaxis30 are possible.
• A[0032]bore35 with a greater diameter is incorporated in the mountingsupport29 for the fixation of the end of the fiber opticlight guide16, in which said bore a cylinder-shapedcarrier bracket36 fits, in which the end of the fiber opticlight guide16 is arranged in such a way that itsfrontal area37 closes flush with the front side of thecarrier bracket36. Opposite thelamp23 thefrontal area37 of the fiber opticlight guide16 is arranged in such a way that depending on the swivel position of the mountingsupport29 more or less light of thelamp23 can be coupled in the fiber opticlight guide16. A glass plate41 is arranged in front of thefrontal area37 for its protection.
• The rotating motion of the mounting[0033]support29 is caused by a drive, which has arotating arm38 which is mechanically connected with the mounting support (29) by means of a rod (39) and abolt40.
• In the swivel position of the mounting[0034]support29 shown in FIG. 3, thefrontal area37 of the fiber opticlight guide16 opposite thelamp23 has a position in which a maximum light quantity can be coupled in the fiber opticlight guide16. With a counter-clockwise rotation of therotating arm38 the mountingsupport29 is also turned counter-clockwise. This causes thefrontal area37 of the opticlight guide16 to move out from the light focus formed by thereflector23, thus causing the quantity of the light coupled in the fiber opticlight guide16 to decrease. Thus by adjusting therotating arm38 it is possible to precisely set the quantity of light coupled in the fiber opticlight guide16 and adapt exactly to the type of object to be examined by theendoscope1.
• In FIG. 4 a further embodiment of the invention's endoscope with[0035]sideview optics11 is shown. As with the embodiment in accordance with FIG. 1, thevideo camera7 with itslens17 is motionless connected with theprobe2 and arranged within the pivotedhollow cylinder6, which is connected on the side turned toward the direction of view with themirror15bearing sideview optics11. In the embodiment according to FIG. 4, however, thehollow cylinder6 is rotated by anelectric motor42 arranged at a distance to thevideo camera7 in theprobe2, whereby theelectric motor42 drives aminiature gear44 by means of aflexible shaft43, which then causes the rotation of thehollow cylinder6. Theelectric motor42 can also be arranged outside theprobe2 near to the probe entry.
• In the same way the[0036]lens17 is driven by anelectric motor45 by means of aflexible shaft46 for the purpose of focusing. The power supply and the control of theelectric motors42 and45 happens in known manner using electric lines and is not shown in FIG. 4. There is also no detailed representation of theflexible shafts43 and46 known from the state of the art, which similar to a tachometer shaft from a plastic hose can exist with a pivoted drive spiral within. Finally, it should be pointed out that the length of theprobe sections2 between thevideo camera7 and theelectric motor42 and between theelectric motors42 and45 is variable and can be adapted to the corresponding purpose of the endoscope. Hereby theelectric motor45 can also be arranged outside of theprobe2 near the probe entry. Moreover, it can be advantageous for specific purposes to replace theelectric motors5,42 and/or45 with motors that are driven by means of media placed under pressure (e.g. compressed-air motors).
• All features portrayed in the description, in the following claims and in the drawings can be essential to the invention both individually and in any given form with each other.[0037]
LIST OF REFERENCE NUMBERS
• [0038]1 Endoscope
• [0039]2 Probe
• [0040]3 Photo camera
• [0041]4 Casing
• [0042]5 Electric motor
• [0043]6 Hollow cylinder
• [0044]7 Video camera
• [0045]8 Casing of the electric motor
• [0046]9 Gear
• [0047]10 Transmission
• [0048]11 Sideview optics
• [0049]12 Arrow, direction of view
• [0050]13 Attachment
• [0051]14 Mount
• [0052]15 Mirror
• [0053]16 Fiber optic light guide
• [0054]17 Lens
• [0055]18 Longitudinal axis
• [0056]19 Casing of the video camera
• [0057]20 Gasket
• [0058]21 Device for coupling of light in16
• [0059]22 Rack
• [0060]23 Lamp, reflector
• [0061]24 Lamp bracket
• [0062]25′ Connecting pin
• [0063]26′ Jack
• [0064]27 Electric power supply
• [0065]28 Plate
• [0066]29 Mounting support
• [0067]30 Axis
• [0068]31 Projection of22
• [0069]32 Projection of29
• [0070]33 Bore
• [0071]34 Bore
• [0072]35 Bore
• [0073]36 Carrier bracket
• [0074]37 Frontal area of16
• [0075]38 Rotating arm
• [0076]39 Rod
• [0077]40 Bolt
• [0078]41 Glass plate
• [0079]42 Electric motor for thesideview optics11
• [0080]43 Flexible shaft for thesideview optics11
• [0081]44 Miniature gear for propelling thesideview optics11
• [0082]45 Electric motor for setting thelens17
• [0083]46 Flexible shaft for thelens17

Claims (14)

1. Endoscope (1) with sideview optics (11),

which is rotated by an electric motor (5,42), and

which has a mirror (15) for deviation and projection of light in a predetermined direction of view (12) on an object to be examined and for reflecting of the image of the object to a lens (17) of a video camera (7) arranged in an endoscope (1),

characterized by the fact

that the video camera (7) is located in the interior of a pivoted hollow cylinder (6) that can be rotated by an electric motor (5,42),

that the sideview optics (11) is mechanically connected with the hollow cylinder (6) on the side turned toward the direction of view, and

that the electric motor (5,42) is arranged behind or next to the video camera (7) in the direction of the object to be photographed by the video camera (7).

2. Endoscope according toclaim 1, characterized by the fact that the video camera (7) is surrounded by a cylinder-shaped casing (19), which forms a clearance with the hollow cylinder (6) and that on the casing (19) at least one gasket (20) is arranged for sealing of the clearance.

3. Endoscope according to one of the preceding claims, characterized by the fact that the electric motor (5) has a gear (9) with which the hollow cylinder (6) can be rotated by means of a hollow gear arranged on its cylinder inner wall.

4. Endoscope according toclaim 3, characterized by the fact that a transmission (10) is arranged between the electric motor (5) and the gear (9).

5. Endoscope according to one of the preceding claims, characterized by the fact that the video camera (7) is mechanically connected with the electric motor (5).

6. Endoscope according to one of the preceding claims, characterized by the fact that the sideview optics (11) is connected with the hollow cylinder (6) by means of a semi-tubular attachment (13).

7. Endoscope according to one of the preceding claims, characterized by the fact that the mirror (15) of the sideview optics (11) is constructed as a prism.

8. Endoscope according toclaim 1 or2, characterized by the fact that the electric motor (5) propels the hollow cylinder (6) by means of a friction gear.

9. Endoscope according to one of the preceding claims, characterized by the fact that the electric motor (5) is constructed as a stepping motor, which consists of electrical windings arranged on the casing (19) and of permanent magnets arranged on the hollow cylinder (6) that enter into electromagnetic interaction with the windings depending on their drive.

10. Endoscope according to one of the preceding claims, characterized by a device (21) for the coupling of light to the fiber optic light guide (16) with a mounting support (29) of the end of the fiber optic light guide (16) turned toward the photo camera (3) that swivels in such a way that in a first swivel position of the mounting support (29) a maximum and in a second swivel position of the mounting support (29) a minimum light quantity can be coupled in the frontal area (37) of the end of the fiber optic light guide (16) attached to the mounting support (29).

11. Endoscope according toclaim 10, characterized by the fact that the device (21) has a lamp with a light-focusing reflector(23), that the fiber optic light guide (16) is attached to the mounting support (29) with the frontal area (37) pointing in the direction of the reflector (23), and that the mounting support (29) can be swiveled around a vertical axis (30) vertical axis (30) lying between the light focus and the reflector (23) between the first and the second swivel positions.

12. Endoscope according toclaim 11 or12, characterized by the fact that a motor driven rotating arm (38) is provided for swiveling the mounting support (29), which is mechanically connected with the mounting support (29) by means of a rod (39) and a bolt arranged outside of the axis (30).

13. Endoscope according toclaim 1, characterized by the fact that the electric motor (42) is connected with the hollow cylinder (6) by means of a flexible shaft (43) and a miniature gear (44).

14. Endoscope according toclaim 1 or13, characterized by the fact that the camera (7) has an adjustable lens (17), which, in order to be adjusted, is connected by means of a flexible shaft to an electric motor (45).

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